Wow what an awesome opportunity to have at such a young age...I wish I could have done that in high school! Is she attending a spanish high school? Is she there with other americans as part of a group program? Unless the teaching english was specified as part of her program, or she offered to do it, I dont think she should feel at all obligated to do that. I would suggest getting as involved in school as possible, find a club that she is interested in, and start making friends. As for the host family situation...that is tough. I studied in Bilbao over the summer, and while I had an awesome family, I had a friend who had what seems like a very similar situation to your daughter's. The family always wanted her to babysit the kids, or teach the family english. She ended up switching host families half way through the program, and was very happy after that. So I would say that if your daughter is truely unhappy in her current situation, look into switching families now, while it is still early in the program. A host family should be the best part of her experience abroad, not detract from it! Good Luck
Kelly